Background and Objectives: To investigate prognostic risk factors and determine the incidence, clinical characteristics, and predictors of heart failure (HF) development in pediatric patients with end-stage kidney disease (ESKD) secondary to steroid-resistant nephrotic syndrome (SRNS). Materials and Methods: We conducted a retrospective cohort study of pediatric patients diagnosed with ESKD secondary to nephrotic syndrome (NS) between 2014 and 2020. Patients were stratified based on clinical outcomes and the occurrence of HF during follow-up. Comparative analyses of clinical characteristics, laboratory parameters, and cardiac assessments were performed across groups. Multivariate logistic regression was used to identify independent risk factors for HF development within the first year and for adverse prognosis at five years. Results: The cohort comprised 172 children with ESKD secondary to NS. Multivariate logistic regression identified HF as an independent risk factor for adverse long-term outcomes in pediatric patients with ESKD. During follow-up, HF developed in 27 patients (15.7%) within the first year after ESKD diagnosis, and in 45 patients (26.2%) by the end of five years. Early HF onset (within the first year) was associated with a significantly reduced five-year survival rate. Independent risk factors for HF development included elevated cardiac troponin I levels (OR = 6.786, 95% CI: 2.326-19.799), a history of cardiac arrhythmias (OR = 2.951, 95% CI: 1.260-6.912), and the presence of left heart enlargement (OR = 23.669, 95% CI: 2.876-194.827), and valvular regurgitation at the initial post-ESKD diagnosis evaluation. Conclusions: HF is associated with markedly reduced survival. Crucially, our findings demonstrate that pre-existing cardiovascular structural abnormalities-specifically left heart enlargement-and elevated cTnI are robust, early predictors of HF. These findings necessitate a paradigm shift in pediatric ESKD management, we advocate for the implementation of systematic baseline echocardiographic and biomarker screening at the immediate onset of ESKD. Identifying these subclinical, yet modifiable, structural changes provide a critical therapeutic window for targeted anti-remodeling interventions to significantly improve long-term prognosis.